26 Tlie Rev. S. Haughton on the Chemical Composition of 

 Table I. — Analyses of Granites from principal Chain. 



No. 1. DaJkey. — Speciiic gravity, 2"6-17. A fine-grained gra- 

 nite containing black and transparent mica. This granite 

 cannot be a ternary compound of quartz, felspar and 

 margarodite. This granite was used in the construction 

 of Kingstown Harbour. 



No. 3. Fox-rock. — Specific gravity, 3'638. A coarse granite, 

 which strikes fire under the hammer; it forms a durable 

 and strong building stone, and has been employed in the 

 ring stones of Trinity College belfry, and in the construc- 

 tion of the O'Connell monument at Glasnevin. 



No. 3. Three Rock. — Specific gravity, 3-653. This granite 

 is rather coarse-grained; it was taken from Woodside 

 Quarry, on the slope of the Three Rock Mountain, and 

 like No. 3, has been used in the construction of the 

 O'Connell monument. 



No. 4. Enniskeiry. — Specific gravity, 2'633. A rather coarse- 

 grained granite, containing veins of black tourmaline. 



No. 5. Balhjknocken. — Specific gravity, 2*636. This granite 

 is the best building stone in the neighbourhood of Dublin, 

 and has been extensively used in the jniblic buildings of 

 this city ; it forms the principal part of the granite used 

 in the belfry and museums of Trinity College. The 

 quarries are situated beyond Blessington, in the county 

 of Wjjcklow. 



No. 6. Killhalhjhugh. — Specific gravitj^, 2-616. This is a fine- 

 grained granite, and works freely ; it has been employed 

 in the construction of the Chapel of Ease in the town of 

 Carlow. 



No. 7. Blackstairs. — Specific gravity, 3-633. A medium- 



